What we know about 64km-long Russian convoy headed for Kyiv

A massive 64-kilometre-long convoy of Russian military vehicles snaking along roads north of Kyiv is being tracked with dramatic satellite images.

The column of Russian tanks, towed artillery, armoured and logistical vehicles, which at times spans three-wide across the entire road, is believed to be under orders to occupy the Ukrainian capital.

Here's what we know so far about the convoy.

What and who is in the convoy?

It is estimated up to 15,000 Russian soldiers are riding with the convoy, which is made up of tanks, armoured vehicles and an array of other artillery and military hardware.

The sheer length of the convoy speaks to the amount of the military power the Russians have amassed to try and take Kyiv.

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Where did the convoy start?

All roads north of Kyiv lead to Belarus, which is where the convoy has come from.

So there was Russian build-up of troops in Belarus?

Correct. For weeks prior to the invasion, Russia amassed forces in Belarus.

Hundreds of Russian military vehicles, aircraft and helicopters were moved to the former Soviet state to participate in what the two allies described as joint exercises.

But after the manoeuvres ended, the Russian forces didn't go home.

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What happened instead?

Satellite imagery from Maxar Technologies showed Russia continued to increase the number of military vehicles, air power and weaponry in Belarus.

From Brest in the east, to Gomel in the west, Russian forces kept popping up at air bases, in towns and even in fields.

Satellite images showed Russia constructed a pontoon bridge across the Pripyat River, which spans Ukraine and Belarus.

The day the invasion began, dozens of Russian military vehicles moved across the bridge.

What kind of Russian force was moved to Belarus before the invasion?

According to NATO, up to 30,000 combat troops, Spetsnaz special operation forces, fighter jets including SU-35, Iskander dual-capable missiles and S-400 air defence systems.

What about reports of the convoy hitting trouble?

The convoy has been slowed by logistical issues, specifically fuel and food shortages, according to a senior US defence official who briefed reporters anonymously to discuss Pentagon intelligence.

Has the convoy been attacked?

That same official said the Russians are likely protecting the convoy, which helps explain why it does not appear to have been attacked.

The airspace over Ukraine is contested by Ukrainian and Russian forces.

The official claimed there are signs of morale problems among Russian troops, many of whom have been drafted, but they declined to say how the Pentagon knew this.

- Reported with CNN